Combined sand elevator and drier



Nov. 6, 1945. J. G. FORSH'ER ET AL 2,388,399

COMBINED SAND ELEVATOR AND DRIER Filed Oct. 15 1942- 2 Sheets-Sheet 1 Jill 1.111 41; 11111111111111 1111111111 J. G Foles'rz L. G. PLANT,

HG. BY

ATTORNEY Nov. 6,- 1945. J. G. FORSTER ET AL 2,388,399

COMBINED SAND ELEVATOR AND DRIER Filed 001:. 15, 1942 2 Sheets-Sheet 2 JG. FOESTE/Z .L. G. PLANT.

INVENTORS ATTORNEY Patented Nov. 6, 1945 COMBINED SAND ELEVATOR AND DRIER John George Forster, Chicago, IlL, and Leland G. Plant, Washington, D. 0.

Application October 15, 1942, Serial No. 462,170 9 Claims. (Cl. 263-8) This invention is for an improvement upon the means of elevating sand to overhead storage bins from which it can be discharged by gravity, and for drying the sand, wherein the functions of elevating and drying sand may be combined to accelerate release of moisture and economize upon the heat required for this process.

-In railway operation large quantities of sand are supplied to locomotives, steam, Diesel and electric, to increase the adhesion of their wheels to the rail. For this purpose it is required that the sand be thoroly dry so that it will not clog in the pipes thru which it is delivered to the rail (from sand boxes on the locomotive).

Supplies of sand are usually received at locomotive servicing points in "open top cars from which it can be shovelled out or dumped by gravity thru drop doors. This sand contains varying quantities of moisture dependent on its source and amount of water, from rain or snow, ab-

sorbed in transit. The sand thus received must,

be stored, dried and delivered in a dry state to the locomotives.

To the date of this invention the drying process has been conducted as a step separate from the operation of elevating the sand to overhead storage. Some arrangements have provided for storing a supply of green sand above the drier apparatus to which it flows by gravity to replace sand the top of the elevator which allows moisture to escape therefrom.

Prior to this invention sand driers in railway use have provided no means for release of moisture by agitation except such slight movement as is incidental to its passing thru the stove drier or steam coil apparatus in which the sand is actuated by gravity. The principle of rotating kilns in which agitation is a large factor is, of course, applicable to sand but in these the sand is carried by gravity in a downward path and elevation of the material as required to effect its storage in an overhead bin must be accomplished in a separate step by other means.

This invention combines the mechanism of a conveyor for elevating sand with the means for applying heat to the sand as it is being elevated. The combination also may include the means for bringing particles of the sand thus warmed into 'contact with the air. It is adapted particularly toutilize a conveyor of the Redler type for elevating sand in a continuous mass up thru an enclosed casing, the invention being accomplished by partially (or wholly) surrounding this casing with a fine for the products of combustion from the fire in a sand drier unit of the conventional stove type.

The means employed for aerating particles of sand, warmed in the process of being elevated, may be found to some extent in the Redler type of conveyor employed as above altho other types of conveying apparatus can be utilized for this purpose. The elevating leg of a Redler conveyor for handling sand can be run at a speed in relation to the rate at which it is fed which will agitate the sand being elevated and discharge it from the top of the casing in a spray of divided particles. Other means may be designed for this purpose in the form of sloping surfaces such as a cone at the apex of which the sand being elevated emerges from the conveyor casing and spreads out in a thin layer flowing down over said surfaces and the sides of said cone.

The operation of this invention preferably takes place inside of an elevated storage bin structure up thru which the flue surrounded conveyor casing rises from the level at which it is fed from a supply source. The sand discharge point at top of said casing is located at suflicient height to fill the bin to its desired capacity. The cone surface surrounding said sand discharge point may also bea baiile plate in connection with the flue surrounding said casing, serving to deflect the hot gases rising therein to a vent, or vents, therefrom and thus transmitting heat from its surfaces to complete drying which proceeds the charging of locomotive bins with sand dried by a stove unit that discharges its gases of combustion into the flue heating means of this invention. In this use of the invention contents of the elevated storage bin becomes partially dried as it is stored, remaining in that condition until drawn upon and dried in a stove unit for use by locomotives.

Use of the invention may be extended, however, to effect a more complete drying of all sand stored in the elevated bin surrounding the conveyor casing and flue. This canbe done during intervals between receipt of green sand from its outside supply source and is accomplished byyreelevating the sand thru the flue encased conveyor casing. In this operation the conveyor casing is supplied with sand drawn from base of the storage bin. By this procedure the sand can be repeatedly agitated in the conveyor casing and spread in thin layers upon cone surfaces while subject to heat transmitted thru the sides of said casing and said conical surfaces from the stove flue above described.

The equipment required for using this invention may also be used as an elevating means for the completely dried sand flowing from the stove unit, either directly or thru an intermediate reservoir. This operation maybe combined with the recirculatin procedure above outlined so that dry sand from the stove together with partially dried sand drawn from base of the elevated bin is re-elevated. Except for intervals when it is required to fumish dry sand for delivery to locomotives, this re-elevation may be continued until the entire contents of the elevated storage bin has been completely freed from moisture.

The apparatus of this invention is also adapted to elevating dry sand from the stove drier or an intermediate reservoir, and discharging it directly to locomotives or into an intermediate bin at a height from which it can be delivered by gravity to locomotives. This adaptation of the invention can be made operative in several ways, one of which is the employment of a valved extension to the conveyor casing at its top discharge point. By this means the sand elevated in the conveyor casing can, at will, either be directed wholly-into the bin intended for storage of green or partially driedsand, or to a compartment for dry sand to be delivered to locomotives.

Figure 1 illustrates a complete facility for receiving supplies of green sand from railway cars, elevating, drying and storing both partially dried sand and fully dried sand in readiness for delivery to locomotives. It is a cross-sectional view of a structure containing the elements which combine to make this invention. Figure 2 is a crosssection of the above structure with its conveyor casing and flue adapted to the purpose of this invention as shown by Figure 1, viewed in plane XX. Figure 3 is an enlarged view of the sleeve valve arrangement appearing at the top of above conveyor casing in position to release sand from the conveyor chain so that it can flow over the sides of the conical surface shown in Figure l, and Figure 4 is another view of the same valve arrangement but in a position that will divert sand elevated by the conveyor from the casing into a chute to the separate storage bin shown in Figure 1.

In the above drawings letter symbols are to designate parts of the invention, its related equipment and supporting structure, as follows:

A, casing in which sand can be conveyed.

B, flue passage surrounding the casing A.

C, chain or other means for conveying sand within casing A.

D, hopper adapted to receive sand by gravity and direct it into the path of a conveyor by which it is removed therefrom.

E, track on which ca'rs supplying green (undrled) sand can discharge into a hopper D,

F, furnace fire in stove for drying sand.

used

G, sand hopper on stove drier.

H, sand screens in stove drier.

I, reservoir for sand from stove as dried.

Iv, valve controlling release of sand from reservoir I.

J, sand storage space within a bin structure.

K, wall structure of a bin adapted to storage of sand.

L, funnel and duct for drawing sand from base of storage J.

Lv, valve in duct L controlling release of sand from base of storage J, to hopper D, and thence into a conveyor by which it can be re-elevated thru easing A, to top of the storage J.

M, valved opening in base of storage J, for feeding sand therefrom to the stove drier.

N, conical roofed bailie surmounting flue B.

O, vent stack from baille B, for release of hot gasses rising in flue B.

P, bin from which a supply of dry sand can be delivered by gravity to locomotives.

Q, spout, valved and hinged as ordinarily provided for supplying dry sand to locomotives from an overhead source.

R, chute thru which bin P can be charged with dry sand when elevated in casing A, by conveyor chain C.

S, valve means adapted to closing access to chute R, while releasing sand elevated in casing A, so that it can flow down over the conical surface of N, or, alternately as directed, be adapted to preventing release of sand from casing A, as elevated, except to chute R, for the purpose of charging bin P, when the sand supplied casing A, is dried.

T, track on which locomotives receive supplies of dry sand thru spout Q.

U, motor for driving a conveyor, if required, for charging the vertical sand elevator thru hopper D, from supply cars on track E.

V, motor for driving the conveyor chain C, to elevate sand thru casing A, partially surrounded by flue B.

W, access door at base of flue B, for cleaning out soot and cinders accumulating in the flue.

Z, return loop of the conveyor chain C.

Use of this invention may comprise one or more of the following steps described in the operation of a facility such as shown in Figure 1, which embraces all elements of which various combinations are claimed for the invention.

The first step is receipt and unloading of green sand from supply cars placed on track E. To accommodate cars of the type having drop doors in its floor, this facility has a hopper below the track E, into which contents of the car is dumped. The track hopper may be sloped to such depth that its contents will flow by gravity down into the conveyor mechanism employed for elevating the sand to an overhead storage bin or, as in Figure 1, this hopper D, may be of shallow construction having horizontal conveying mechanism with a conveyor chain C, actuated by motor U, by which means its contents is fed to an elevator conveyor in casing A, surrounded by the flue B preferably on three sides as shown in Figure 2, to afford access to the chain C, by unbolting the cover plate indicated in this drawing.

aeaaaao stove maintained for drying said supplied to a hopper G, over the stove as shown in Figure 1. Thetype of stove best adapted for use with this invention is that in which the sand lies on top of screens H, and falls thru into a reservoir below the stove as it becomes dry due to the heat rising from a fire F, in the stove furnace as illustrated. Temperature of the sand being elevated ployed for the purpose of this invention and the accompanying drawings illustrate a typical construction of this conveyor. It operates upon the principle of a jointed chain having prongs or flat projections at each joint, the chain being drawn thru a closed casing of a cross-area which allows some clearance for passage of the prongs or projections transverse to the chain links. The conveyed material is entrained by the chain with its projections and ordinarily flows thru the casing, horizontally, vertically or in an inclined direction, in a mass all particles of which travel approximately at the speed of the chain. However, the size and speed of a conveyor chain C, as in Figure 1, may be so proportioned in the vertical casing A, relative to the rate at which sand is fed to this conveyor from hopper D, that the sand being elevated will not fill the casing or else the chain C will move up thru the casing A at a faster speed than the mass of sand being conveyed therein, The effect in either case will be to bring some air in contact with the sand before it reaches the top of casing A, and effect a release of moisture from the heated sand as it is discharged from the top of this conveyor casing.

To further promote release of moisture from the heated sand as it is discharged from thevertical conveyor at the top of casing A, there may be provided a sloping surface such as the cone N, surrounding the opening of said casing. Sand released from the conveyor will tend to spread out and fiow down upon the surface and sides of this conical structure in a thin layer favorable to the release of moisture therefrom. To make this step more effective the surface N, may be constructed as a baffle for the fiue B, so that it can also impart some heat to the sand spread out on its upper surface. If constructed as an extension to the flue passage B, the baille N, may have its vent stack 0, placed out of line to the flue passage B,

as shown in Figure 1.

In the arrangement of Figure 1, for utilizing this invention the rate at which sand is elevated thru casing A, by chain C, and delivered to storage J, is determined by the time in which it is desired to unload a quantity of sand from the supply car. The amount of drying accomplished during this process of unloading and elevating the sand depends upon the amount of heat supplied by combustion in the sand stove or from other sources. Ordinarily, only a portion of the moisture in green sand is expelled in the process of elevating it as it is unloaded from supply cars. Complete drying of the sand stored in a partially dried state can be accomplished in a single step by passage thru a sand stove from a hopper G, to reservoir 1, during which process the sand passes thru screens H, gauged to the required fineness for dried sand supplied to locomotives. The customary procedure has been to dry sand in this manner approximately at the rate it can be used, allowing for the quantity that can be stored in a reservoir such as I, at or below stove level, and in an overhead bin such as 1?, from which it can be delivered to locomotives by gravity, as required. The present invention introduces new means for utilizing the heat in gases of combustion from the fire F, in the process above described, which heat has previously been wasted.

As shown in Figure l, the means for elevating dry sand from reservoir I, to bin P, may be combined with the conveyor mechanism of this invention for simultaneously elevating and drying green sand. Figures 3 and 4, illustrate a practical means for thus utilizing the conveying mechanism of this invention as a means for elevating dry sand from reservoir 1, to bin P. In Figure 3, the sleeve valve S, shown in a raised position closes access to chute R, thru which dry sand is directed into bin P, but allows sand elevated in casing A, by chain 0, to flow down over the conical surface of N, and into storage J. Valve S, as shown in Figure 4, can be lowered, at will, to efiect. an extension to the casing A, so

that all sand elevated therein by chain C, will b directed into chute R, thence to bin P.

Alternate means for elevating the dried sand from reservoir I, to bin P, may be employed with this invention. Such, for instance,.as compressed air in an arrangement commonly employed wherein the reservoir 1', after being filled with dry sand, is sealed to the atmosphere except for a delivery pipe to the overhead bin and then charged with compressed air at approximately 70 to pounds pressure which, in seeking to :escape thru said sand delivery pipe, entrains the dry sand from said reservoir and carries it into bin P, from which the air is vented. In lieu of this the present invention can be used to conserve compressed air which requires considerable power to generate and to eliminate the excessive wear that occurs upon a pipe duct subjected to abrasive action of sand propelled by compressed air when employed to convey dry sand from a reservoir I, to elevated bin P. Also, this adaptation of the invention avoids the cost of installing separate elevating machinery of use only for elevating dry sand in the manner described.

The space ordinarily provided for dry sand" is v limited to that of a reservoir filled from the drier and the capacity of overhead bins from which sand is supplied to locomotives by gravity. In most installations this does not exceed five to ten tons and operation of the sand stove or equivalent drying means must be conducted at a rate approximating actual delivery of the dry sand to locomotives.

sand by which operation the contents'of a green sand storage space such as J, can be converted into a storage space filled with dry sand.

The above feature of this invention is accomplished in a very simple manner by providing means such as a funnel and duct L, with valve Lv. stora e J, and by opening valve Lv this sand is directed thru the duct L, into the hopper D, and r The storage space provided for green sand is ordinarily sufficient to accom- The funnel draws sand from the base ofthence to the conveyor in which it is elevated by chain C, thru casing A. This practice of the invention is accompanied by continuous operation of the stove drier so that products of combustion therefrom will serve as a heating medium upon the sand being re-elevated. Except for such intervals during which it is necessary to recharge the locomotive delivery bin P, with dry sand from reservoir 1', dry sand flowing from the stove to reservoir 1', can be diverted therefrom thru valve Iv into hopper D, and re-eievated along with the partially dried sand supplied to the same hopper D, from storage space J, thru duct L, as above described. Continuation of this procedure will eventually dry all of the sand in storage converting space J into a dry sand storage of large capacity which can be drawn on as required until a fresh supply of green sand is received. During this interval, once the entire contents of Storage J is dried as described, it is not necessary to maintain a fire F in the sand stove drier with resulting economy in attendance and maintenance cost.

For this invention the following is claimed.

We claim:

1. An apparatus of the character described comprising an upright tubular casing, means for supplying sand to the lower end of said casing, sand elevating means within said casing, a storage receptacle, an elevated chute for supplying sand to a locomotive for track sanding purposes, valve controlled outlet means for said casing at the upper portion thereof adapted to selectively deliver sand from said elevating means to said storage receptacle or to said chute, said storage receptacle having a valved outlet for returning sand by gravity to the lower portion 01 the casing, and means for heating the sand in the course of its return, said heating means comprising a stove located between said valved outlet and the lower portion of the casing and having an outlet duct. for hot exhaust gases, and a heating jacket surrounding said casing for preliminarily drying the sand during the course of elevation, said heating jacket communicating with said outlet duct.

2. In an apparatus of the character described, an upright tubular casing, means for supplying material to be treated to the lower end of the casing, sand elevating means within the casing, a heating jacket surrounding the casin for preliminarily drying sand during the course of elevation, an elevated sand storage receptacle adapted to receive sand delivered from the upper end of said casing, stove means for drying sand delivered by gravity from the storage receptacle, a hot gas outlet from said stove means communicating with said heating jacket, a collecting hopper at the bottom of said casing arranged to receive dried sand from said stove means and. to deliver it to said elevator, said casing having selectively controlled outlets at the upper portion thereof adapted to selectively deliver sandfrom the elevating means to said storage receptacle or to a separate destination.

3. An apparatus of the character described, comprisinga storage receptacle, an upright tubular casing extending through said receptacle, sand elevating means within said casing, and means for heating said sand during the course of elevation, comprising a heating jacket through which hot gases are passed upwardly to heat the casing, said jacket having a sloping baflie at the top thereof against the lower side of which hot gases are passed, and said casing having a discharge outlet just above said baiile whereby sand delivered by said elevating means will flow in a thin stream over the heated baffle, and thence into the storage receptacle.

4. In a device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having selectively controlled upper outlets, one opening into the storage bin and the other comprising a chute for delivering sand by gravity to a. locomotive for track sandin purposes, a sand supply hopper at the lower portion of the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said supply hopper to said outlet, means for at least partially drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by ravity to the supply hopper at the lower portion of the casing, and sand heating means interposed between said valved outlet and the supply hopper.

5. In a device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having selectively controlled upper outlets, one opening into the storage bin and the other comprising a chute for delivering sand by gravity to a locomotive for track sanding purposes, a, sand supply hopper at the lower portion of the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said supply hopper to said outlet, means for at least partially drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by gravity to the supply hopper at the lower portion of the casing, and heating means for drying the sand in passing from the storage bin to the supply hopper.

6. In a device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having selectively controlled upper outlets, one opening into the storage bin and the other comprising a chute for delivering sand by gravity to a locomotive for track sanding purposes, a. sand supply hopper at the lower portion of the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said supply hopper to said outlets, means for at least partially drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by gravity to the supply hopper at the lower portion of the casing, and means for drying the sand in passing from the storage bin to the supply hopper, said bin also having a second valved outlet provided with achute for returning sand to the hopper and bypassing the drying means.

'1. In a device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having selectively controlled upper outlets, one opening into the storage bin and the other comprising a chute for delivering sand by gravit to a locomotive for track sanding purposes, a sand supply hopper at the lower portion of the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said suptially drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by gravity to the supply hopper at the lower portion of the casing, and means for drying the sand in passing from the storage bin to the supply hopper, said drying means comprising a stove located between said valved outlet and the supply hopper and having an outlet flue surrounding the upright casing.

8. Ina device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having a pair of upper outlets, a sleeve valve selectively controlling said outlets, one outlet opening into the storage bin and the other comprising a chute for delivering sand by gravity to a locomotive for track sanding purposes, a sand supply hopper at the lower portionof the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said supply hopper to said outlet, means for at least partially drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by gravity to the supply hopper at the lower portion of the casing, and said tubular casing having a downwardly inclined distributing spreader below the outlet to the storage bin.

9. In a device of the character described, an elevated bin adapted for storage of sand, an upright tubular casing having its upper portion extending through said bin and having selectively controlled upper outlets, valve means for controlling said upper outlets, one outlet opening into the storage bin and the other comprising a chute for delivering sand by gravity to a locoinotivefor track sanding purposes, a sand supply hopper at the lower portion of the casing, means for supplying moist sand to said hopper, means for elevating sand through said casing from said supply hopper to said outlet, means for at least partially'drying the sand during the course of elevation, said bin having a valved outlet at the lower portion thereof for returning sand by gravity to the supply hopper at the lower portion of the casing, said tubular casing having a downwardly inclined distributing spreader below the outlet to the storage bin, and means for supplying heat to the underside of said spreader.

JOHN GEORGE FORSTER. LELAND G. PLANT, 

